1. Field of the Invention
The present invention relates to a safety device for a brush of a vacuum cleaner and more particularly, to a safety device for a brush of a vacuum cleaner, which can prevent a safety accident induced by the power brush of the vacuum cleaner
2. Description of the Prior Art
A vacuum cleaner is a device for absorbing external dust or other foreign substances through a strong sucking force generated by the driving of a motor provided in the body of the vacuum cleaner. The sucked dust or the foreign substances are captured by a dust collecting envelope installed in a dust collecting compartment and cleaned air is exhausted out through a driving compartment.
Generally, vacuum cleaners are classified into canister-type vacuum cleaners and upright-type vacuum cleaners. A canister-type vacuum cleaner includes a body mounted on wheels and a hose assembly for sucking dust or other foreign substances into the body. A suction generating device such as a suction fan, a motor for driving the suction generating device, and a disposable dust container for filtering dust or other foreign substances from air sucked by the vacuum cleaner, are positioned in the body.
An upright-type vacuum cleaner has a constitution which is similar to that of the canister-type vacuum cleaner. However, the upright-type vacuum cleaner differs in that it vacuums a surface directly beneath its body, so a hose assembly is not required.
These days, the canister-type vacuum cleaner is more frequently used than the upright-type vacuum cleaner.
FIG. 1 illustrates a canister-type vacuum cleaner 100. Vacuum cleaner 100 includes a floor cleaning unit 110, a canister unit 120 and a hose assembly 130 extended between floor cleaning unit 110 and canister unit 120.
Floor cleaning unit 110 includes a main brush (not shown) or a suction nozzle (not shown), and the like. Floor cleaning unit 110 is detachably connected to hose assembly 130. Hose assembly 130 comprises a rigid wand 132 and a flexible hose 134. Hose assembly 130 is pneumatically connected to a dust collecting compartment (not shown) of canister unit 120 through a suction hose connector 136.
Canister unit 120 mainly includes a hood 122, a cover 124 and a body 126. Hood 122 encloses the dust collecting compartment and is pivotally installed onto body 126 so that the dust collecting compartment can be opened and closed. Hood 122 is provided with an inlet opening 127 formed through hood 122 for receiving hose assembly 130. Hood 122 also is provided with a transparent window 128 for notifying the user of the dust collecting state. Cover 124 encloses a motor compartment (not shown) where an electric motor and a suction fan driven by the electric motor are positioned.
In the vacuum cleaner having the above-mentioned constitution, a strong sucking force is generated by the rotation of the motor installed at the driving compartment in the body during the use of the vacuum cleaner. The dust sucked into the floor cleaning unit (brush head) by the sucking force is collected in the dust envelope detachably installed in the dust collecting compartment and the filtered air is exhausted out through the driving compartment.
Recently, a power brush which is provided with a motor in a cleaning unit and rotates a brush roller, is developed and applied to the vacuum cleaner for increasing the sucking efficiency of the vacuum cleaner on the dust. In the power brush, when an electric source is applied and the power is on state, the driving motor continues its driving and the brush roller always rotates. Only when an electric switch is off, the electric source supplied to the driving motor is cut off and the driving of the motor is stopped.
FIG. 2 is a schematic perspective view for showing the power brush for the conventional vacuum cleaner. As illustrated in FIG. 2, the power brush is provided with a rotating roller 205 which rotates by the rotation of motor 240 and a moving roller 218 positioned at the front portion of the brush in a brush body 201. Rotating roller 205 rotates by motor 240 during the cleaning using the vacuum cleaner to increase the dust sucking efficiency of the vacuum cleaner. In the power brush, the cleaning efficiency can be increased through the rotation of rotating roller 205 during the cleaning. However, the rotation of rotating roller 205 when the user does not cleaning, is unnecessary. Moreover, this rotation becomes a factor of safety accidents. Accordingly, the rotation of rotating roller 205 should be stopped when the vacuum cleaner is not used.
Therefore, in the vacuum cleaner having the power brush, a safety device for the power brush of the vacuum cleaner, which stops the rotation of rotating roller 205 when the vacuum cleaner is not contemporarily used to prevent safety accidents, has been reported. FIG. 3 is a schematic perspective view for showing a safety device for the power brush of the conventional vacuum cleaner.
A safety device 250 illustrated in FIG. 3 includes a pressing member 212 which is provided at one front side of brush body 201. Pressing member 212 is rotatably supported at one front side of brush body 201, by rotating shafts 213a and 213b which are formed at both rear sides of pressing member 212. At the first front side of pressing member 212, a pair of front protrusive portions 212b protruded downward by constant angle with an angle of inclination, are provided. And at the upper portion of the second side facing the first side where front protrusive portions 212b are formed, a cam 212a is formed. At the front end portion of front protrusive portions 212b, joining holes 214 are formed. Into joining holes 214, a rotating shaft 219 of moving roller 218 is inserted.
An elastic piece 217 of a switch 220 is brought into contact with the upper surface of cam 212a. At the front upper portion of pressing member 212, a protrusive boss 215 is formed. At protrusive boss 215, a compressive spring 216 is inserted to provide an electric source to brush body 201 and to impart a rotating force to pressing member 212 to the direction A.
Moving roller 218 provided at front protrusive portion 212b of pressing member 212 facilitates the movement of brush body 201.
When the user uses the vacuum cleaner, moving roller 218 contacts the bottom and pressing member 212 rotates to the reverse direction of the arrow A from the initial state. Accordingly, spring 216 is compressed and cam 212a rotates simultaneously to press elastic piece 217. Then, the applying state of the electric current is kept and the electric current is supplied to the motor.
Next, when the user lifts brush body 201, moving roller 218 is separated from the bottom. At this time, pressing member 212 is pressed downward by spring 216 and rotates to the direction of arrow A. Then, cam 212a rotates and elastic piece 217 of switch 220 moves downward along the contacting surface of cam 212a to transform into an off state. Accordingly, the electric current supplied to the driving motor of the power brush is cut off.
In the safety device for the power brush of the conventional vacuum cleaner, the brush should be turned over when assembling the moving roller and the switch. Therefore, the assembling process is very difficult and complicated. And the manufacturing cost is increased.